Transflective LCD device and fabrication method thereof

ABSTRACT

A transflective liquid crystal display device including: first and second transparent substrates facing each other with a reflective portion and a transmissive portion; gate and data lines over the first transparent substrate perpendicularly crossing each other and defining pixel regions; a thin film transistor connected to the gate and data lines in the pixel region; an insulator in the thin film transistor on the first substrate covering the gate line; a passivation layer in the reflection portion on the insulator and on the thin film transistor, a pixel electrode in the reflective and transmissive portions, wherein the pixel electrode contacts both the passivation layer in the reflective portion and the insulator in the transmissive portion; a reflector on the pixel electrode in the reflective portion; color filters on a rear surface of the second transparent substrate, the color filters having through holes; column spacers formed between the reflector and the color filters, each column spacer corresponding in position to each through hole; a common electrode under the color filters; and a liquid crystal layer interposed between the common electrode and the pixel electrode.

This application is a divisional of U.S. patent application Ser. No.11/404,855, filed Apr. 17, 2006 now U.S. Pat. No. 7,570,340, which is adivisional of U.S. patent application Ser. No. 10/811,981, filed Mar.30, 2004 now U.S. Pat. No. 7,053,974, which claims the benefit of KoreanPatent Application No. 2003-0021390, filed in Korea on Apr. 4, 2003,which is hereby incorporated by reference for all purposes as if fullyset forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display device and amethod of fabricating a liquid crystal display device, and moreparticularly, to a transflective liquid crystal display device havingthrough holes in color filters and a method of fabricating the same.

2. Description of Related Art

As the use of information technology increases, the need for flat paneldisplays with thin profiles, light weight, and lower power consumptionhas increased. Accordingly, various flat panel display (FPD) devices,such as liquid crystal display (LCD) devices, plasma display panel (PDP)devices, field emission display devices, and electroluminescence display(ELD) devices, have been developed.

Presently, liquid crystal display (LCD) devices with light weight, thinprofiles, and low power consumption are commonly used in officeautomation equipment and video units. LCD devices typically use a liquidcrystal (LC) interposed between upper and lower substrates and make useof optical anisotropy of the LC. Because molecules of the LC are thinand long, an alignment direction of the LC molecules may be controlledby the application of an electric field to the LC molecules. When thealignment direction of the LC molecules is properly adjusted, the LC maybe aligned such that light is refracted along the alignment direction ofthe LC molecules to display images.

In general, LCD devices are divided into transmissive-type LCD devicesand reflective-type LCD devices according to whether the display deviceuses an internal or external light source. The transmissive-type LCDdevice includes an LCD panel and a backlight device, wherein theincident light produced by the backlight device is attenuated duringtransmission so that the actual transmittance is only about 7%. As aresult, the transmissive-type LCD device requires a relatively highinitial brightness, whereby the electrical power consumption required bythe backlight device increases. Accordingly, a relatively heavy battery,which cannot be used for an extended period of time, is needed to supplysufficient power to the backlight device.

The reflective-type LCD has been developed, which overcomes theseproblems. Because the reflective-type LCD device uses ambient lightinstead of a backlight device and a reflective opaque material is usedas a pixel electrode, the reflection-type LCD device is light and easyto carry. In addition, because the power consumption of thereflective-type LCD device is reduced, it may be used in a personaldigital assistant (PDA). However, the reflective-type LCD device iseasily affected by its surroundings. For example, because ambient lightin an office differs largely from that outdoors, the reflective-type LCDdevice can not be used where the ambient light is weak or does notexist. In order to overcome the problems described above, atransflective-type LCD device has been developed, wherein the device hasboth a transmissive mode and a reflective mode.

FIG. 1 is a cross-sectional view illustrating a transflective liquidcrystal display device according to the related art.

The transflective liquid crystal display device according to the relatedart includes an array substrate 10, a color filter substrate 50, and aliquid crystal layer 80 interposed between the array and color filtersubstrates 10 and 50. The color filter substrate 50 includes a blackmatrix 53 on a rear surface of a transparent substrate 51. Red (R),green (G) and blue (B) color filters 55 a, 55 b and 55 c are also formedon the rear surface of the transparent substrate 51 while covering theblack matrix 53. An overcoat layer 63 is formed on a rear surface of thered (R), green (G) and blue (B) color filters 55 a, 55 b and 55 c. Theovercoat layer 63 protects the color filters 55 a, 55 b and 55 c.Additionally, a common electrode 65 is formed on a rear surface of theovercoat layer 63.

The array substrate 10 includes a thin film transistor T including agate electrode 15, a semiconductor layer 20, a source electrode 23 and adrain electrode 25 on a transparent substrate 11 where a gate line (notshown) and a data line 21 cross. A gate insulating layer 17 isinterposed between the gate electrode 15 and the semiconductor layer 20and contacts the transparent substrate 11. A passivation layer 30 isformed on the gate insulating layer 17, covers the thin film transistorT, and has a drain contact hole 35 exposing a portion of the drainelectrode 25. A pixel electrode 40 is formed on the passivation layer 30and contacts the drain electrode 25 through the drain contact hole 35. Areflector 45 is formed on peripheral portions of the pixel electrode 40.In the array substrate, an area where the reflector 45 is formed becomesa reflective portion RA, and an area where the reflector 45 is notformed becomes a transmissive area TA.

Column spacers 70, which are interposed between the array and colorfilter substrates 10 and 50, form a cell gap where the liquid crystallayer is interposed. Each column spacer 70 corresponds in position tothe black matrix 53 of the color filter substrate 50.

The transflective liquid crystal display device having the structure ofFIG. 1 has a disadvantage due to the difference in the light efficiencybetween reflective mode and transmissive mode operation. Thus, theaforementioned liquid crystal display device produces unstablebrightness and color reproduction, which are different between thereflective mode and the transmissive mode.

When the transflective liquid crystal display device operates in atransmissive mode, a backlight (not shown) disposed underneath the arraysubstrate 10 generates light directed toward the array substrate 10 suchthat the light from the backlight passes only once through the colorfilters 55 a, 55 b and 55 c. However, when the transflective liquidcrystal display device operates in a reflective mode, ambient lightincident from the surroundings passes through the color filters 55 a, 55b and 55 c, and then is reflected by the reflector 45 back towards thecolor filters 55 a, 55 b and 55 c. Therefore, the ambient light passestwice through the color filters 55 a, 55 b and 55 c. This two-timepassage through the color filters 55 a, 55 b and 55 c results in thereflective mode reproducing better color than the transmissive mode.However, the two-time passage decreases the brightness in the reflectivemode versus the transmissive mode.

To overcome those problems, it has been suggested that the liquidcrystal layer between the array and color filter substrates have twodifferent cell gaps and/or that each color filter is formed to have adifferent thickness between the reflective portion and the transmissiveportion. Thus, the color reproduction and the brightness are adjusted tobe the same regardless of whether the transflective liquid crystaldisplay device is operated in the reflective mode or in the transmissivemode. However, these modifications also have some disadvantages.

Today when a transflective liquid crystal display device is utilized inmobile phones or PDAs, the image quality becomes an important issue insatisfying buyer's demands. For good image quality, a high resolution isrequired in the transflective liquid crystal display device. Thus, thetransflective liquid crystal display device needs to have many pixelsper unit area such that individual pixels are smaller as compared to thepixels in a conventional liquid crystal display device. However, if thepixel size for the transflective liquid crystal display device isreduced, the reflective portion in the transflective liquid crystaldisplay device is also reduced and a decrease in brightness results.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a transflective liquidcrystal display device and method of fabricating the same thatsubstantially obviates one or more of the problems due to limitationsand disadvantages of the related art.

An advantage of the present invention is to provide a transflectiveliquid crystal display device to produce uniform color purity anduniform color reproduction.

Another advantage of the present invention is to provide a method offabricating a transflective liquid crystal display device to produceuniform color purity and uniform color reproduction.

Another advantage of the present invention is to provide a transflectiveliquid crystal display device and a method of fabricating the same,which produce uniform and stable brightness.

Another advantage of the present invention is to provide a transflectiveliquid crystal display device and a method of fabricating the samehaving high transmittance and color purity.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, atransflective LCD device including: first and second transparentsubstrates facing each other with a reflective portion and atransmissive portion; gate and data lines over the first transparentsubstrate perpendicularly crossing each other and defining pixelregions; a thin film transistor connected to the gate and data lines inthe pixel region; an insulator in the thin film transistor on the firstsubstrate covering the gate line; a passivation layer in the reflectionportion on the insulator and on the thin film transistor; a pixelelectrode in the reflective and transmissive portions, wherein the pixelelectrode contacts both the passivation layer in the reflective portionand the insulator in the transmissive portion; a reflector on the pixelelectrode in the reflective portion; color filters on a rear surface ofthe second transparent substrate, the color filters having throughholes; column spacers formed between the reflector and the colorfilters, each column spacer corresponding in position to each throughhole; a common electrode under the color filters; and a liquid crystallayer interposed between the common electrode and the pixel electrode.

In another aspect, a transflective LCD device, including: first andsecond transparent substrates facing each other with a reflectiveportion and a transmissive portion; gate and data lines over the firsttransparent substrate perpendicularly crossing each other and definingpixel regions; a thin film transistor connected the gate and data linesnear in the pixel region; an insulator in the thin film transistor onthe first substrate with covering the gate line; a passivation layer inthe reflective portion on the insulator and on the thin film transistor;a pixel electrode in the reflective and transmissive portions, whereinthe pixel electrode contacts both the passivation layer in thereflective portion and the insulator in the transmissive portion; areflector on the pixel electrode within the reflective portion; red,green and blue color filters on a rear surface of the second transparentsubstrate, the red, green and blue color filters corresponding to pixelregions, wherein some of the red, green and blue color filters havethrough holes and some do not have through holes; column spacers formedbetween the reflector and the color filters, each column spacercorresponding in position to a color filter that does not have a throughhole; a common electrode under the color filters; and a liquid crystallayer interposed between the common electrode and the pixel electrode.

In another aspect, a method of forming a color filter substrate for usein a transflective liquid crystal display device, including: forming acolor resin on a transparent substrate having reflective andtransmissive portions; disposing a mask over the color resin;irradiating light to the color resin through the mask; forming colorfilters having through holes; forming an overcoat layer over thetransparent substrate to cover the color filters; forming column spacerson the overcoat layer, wherein each column spacer corresponds inposition to the through hole; and forming a transparent pixel electrodeon the overcoat layer exposed between the column spacers.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain principles of theinvention. In the drawings:

FIG. 1 is a cross sectional view illustrating a transflective liquidcrystal display device according to a related art;

FIG. 2 is a plan view illustrating a transflective liquid crystaldisplay device having a high resolution according to a first embodimentof the present invention;

FIG. 3 is a cross sectional view taken along a line III-III of FIG. 2;

FIG. 4 is a cross sectional view taken along a line IV-IV of FIG. 2;

FIG. 5 is a schematic diagram illustrating a transflective liquidcrystal display device having a high resolution according to a secondembodiment of the present invention;

FIG. 6 is a cross sectional view taken along a line VI-VI of FIG. 5; and

FIGS. 7A and 7E are cross sectional views illustrating process steps offorming the color filter substrate of FIG. 4 according to the presentinvention.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings.

FIG. 2 is a plan view illustrating a transflective liquid crystaldisplay device having a high resolution according to a first embodimentof the present invention.

In FIG. 2, gate lines 113 are formed transversely on a first transparentsubstrate and a gate electrode 115 protrudes from the respective gateline 113. The gate lines and electrodes 113 and 115 may be formed of ametallic material. Data lines 121 cross the gate lines 113 and aresubstantially perpendicular to the gate lines 113. Also, a sourceelectrode 123 extends from the source line 121 over one end portion ofthe gate electrode 115. Pairs of the gate and data lines 113 and 121define pixel regions P. A drain electrode 135 is spaced apart from andfaces the source electrode 123 across the gate electrode 115. The drainelectrode 135 also overlaps the other end portion of the gate electrode115. The gate electrode 115 and the source and drain electrodes 123 and125 constitute a thin film transistor T with a semiconductor layer 120that is interposed between the gate electrode 115 and the source anddrain electrodes 123 and 125. As shown in FIG. 2, the thin filmtransistor T is located near a crossing of the gate and data lines 113and 121.

In each pixel region P, a pixel electrode 140 is disposed contacting thedrain electrode 135 through a drain contact hole 135. The pixelelectrode 140 is formed of a transparent conductive material, such asindium-tin-oxide (ITO), and overlaps edge portions of the gate and datalines 113 and 121. The pixel region P is divided into a reflective areaRA and a transmissive area TA. The reflective area RA includes thereflector, while the transmissive area TA does not include thereflector. Like the pixel electrode 140, the reflector overlaps the edgeportions of the gate and data lines 113 and 121. Moreover, the reflectorfunctions to reflect ambient light incident from outside the displaydevice such that the reflector makes the transflective liquid crystallayer operate in a reflective mode. The reflector may be a metallicmaterial selected from a group including aluminum (Al), aluminum alloy(e.g., AlNd), titanium (Ti), copper (Cu), molybdenum (Mo) etc.

Color filter patterns 155 a, 155 b and 155 c having red (R), green (G)and blue (B) colors are formed on a second transparent substrate thatfaces the first transparent substrate. Each of the color filter patterns155 a, 155 b and 155 c faces and corresponds to a pixel region P, andoverlaps edge portions of the gate and data lines 113 and 121 like thepixel electrode 140. Each color filter pattern 155 a, 155 b or 155 c hasa through hole TH in a portion corresponding to the reflective area RA.Unlike the related art shown in FIG. 1, the transflective liquid crystaldisplay device does not include a black matrix among the color filterpatterns 155 a, 155 b and 155 c. Although not shown in FIG. 2, a columnspacer is disposed in each through hole TH.

FIGS. 3 and 4 are cross sectional views taken along lines III-III andIV-IV of FIG. 2, respectively, and illustrate array elements of thetransflective liquid crystal display device.

As shown in FIGS. 3 and 4, the transflective liquid crystal displaydevice includes an array substrate 110, a color filter substrate 150,and a liquid crystal layer 180 interposed between the array and colorfilter substrates 110 and 150.

On the array substrate 110, the thin film transistor T includes the gateelectrode 115, the semiconductor layer 120, the source electrode 123 andthe drain electrode 125 on a transparent substrate 111 near the crossingof the gate line (reference 113 of FIG. 2) and a data line 121. A gateinsulating layer 117 is interposed between the gate electrode 115 andthe semiconductor layer 120 and contacts the transparent substrate 111.The source electrode 123 overlaps one end portion of the semiconductorlayer 120, and the drain electrode 125 overlaps the other end portion ofthe semiconductor layer. Thus, the source and drain electrodes 123 and125 face each other across the semiconductor layer 120. A passivationlayer 130 is formed on the gate insulating layer 117 covering the thinfilm transistor T. The passivation layer 130 is formed of a lowdielectric insulating material, for example, benzocyclobutene (BCB) orphoto-acryl resin, and has a drain contact hole 135 exposing a portionof the drain electrode 125. In the present invention, the passivationlayer 130 is formed only in the reflective area RA, not in thetransmissive area TA. Thus, a cell gap between the array substrate 110and the color filter substrate 150 is divided into two parts withdifferent heights: a first cell gap “d1” and a second cell gap “d2”where the liquid crystal layer 180 is interposed. Namely, the first cellgap “d1” having a first height corresponds to the transmissive area TA,and the second cell gap “d2” having a second height corresponds to thereflective area RA. The first height is larger than the second height.The reason for forming the different heights between the reflective areaRA and the transmissive area TA is to increase the light transmissivityin the transmissive mode.

It is also possible in the present invention that the passivation layer130 is formed in the transmissive area TA, but it will have a smallerthickness than that in the reflective area RA. Additionally, it is alsopossible that the passivation layer 30 is formed over the entire gateinsulating layer 117 with a uniform thickness, and thus the cell gap hasthe same height regardless of the reflective and transmissive areas RAand TA.

The pixel electrode 140 of the transparent conductive material is formedin the pixel region P contacting both the passivation layer 130 in thereflective area RA and the gate insulating area 117 in the transmissivearea TA. The pixel electrode 140 also contacts the drain electrode 125through the drain contact hole 135. As described with reference to FIG.2, the pixel electrode 140 overlaps the edge portions of the gate line(reference 113 of FIG. 2) and the data line 121, such that the pixelelectrode 140 is spaced apart form neighboring pixel electrodes of theneighboring pixel regions. Namely, the gaps between the neighboringpixel electrodes exist in a position over the gate and data lines. Areflector 145 is formed on the pixel electrode 135 only within thereflective area RA. An area where the reflector 145 is formed becomesthe reflective area RA, and an area where the reflector 145 is notformed becomes the transmissive area TA. At this time, because thereflector 145 covers the thin film transistor T and the edge portions ofthe gate and data lines 113 and 121, the reflector 145 acts as a blackmatrix by preventing light leakage in the thin film transistor T.

In the color filter substrate 150 facing the array substrate 110 red(R), green (G) and blue (B) color filters 155 a, 155 b and 155 c arealso formed on a rear surface of a second transparent substrate 151.Each of the red (R), green (G) and blue (B) color filters 155 a, 155 band 155 c corresponds to a pixel region P, and has the through hole THin the reflective area RA (or the reflector 145). An overcoat layer 163is formed on a rear surface of the red (R), green (G) and blue (B) colorfilters 155 a, 155 b and 155 c. The overcoat layer 163 protects thecolor filters 155 a, 155 b and 155 c and planarizes their surfaces.Additionally, a common electrode 165 is formed on a rear surface of theovercoat layer 163. A column spacer 170 is formed on the overcoat layer163 in position corresponding to the through hole TH. The size of thethrough hole TH is determined depending on how much brightness and colorpurity the transflective liquid crystal display device requires in thereflective mode to match the buyer's demands, because there is no colorresin in the through hole TH. If the through hole TH has a larger size,the transflective liquid crystal display device will have an increasedbrightness and a decreased color purity in the reflective mode. On thecontrary, if the through hole TH has a smaller size, the transflectiveliquid crystal display device will have a decreased brightness and aincreased color purity in the reflective mode. Therefore, the brightnessand the color purity are in an inverse relationship to each other. Tomeet the buyer's demands, the brightness and the color purity aredetermined by controlling the size of the through hole TH in the presentinvention.

Furthermore, it is important that the column spacer 170 is formed tocorrespond in position to the through hole TH. The column spacer 170provides and maintains a space of a predetermined distance between thearray substrate 110 and the color filter substrate 150.

Because the transflective liquid crystal display device of the presentinvention has to have a high resolution, a black matrix is not utilized.Further, because the liquid crystal display device of the presentinvention is transflective, the device includes the transmissive area TAand the reflective area RA in the pixel region P. In order to improvethe brightness and color purity when the liquid crystal display deviceoperates in the reflective mode, the through hole TH is formed in eachcolor filter in the reflective area RA. Further, the column spacer 170is formed corresponding in position to the through hole TH in order toenhance the efficiency of the pixel region P. In the present inventionthe column spacer 170 may be larger in area than the through hole TH.The column spacer 170 may be formed of one of benzocyclobutene (BCB),photo-acryl resin, cytop and perfluorocyclobutene (PFCB), so that thecolumn spacer 170 does not reduce brightness in the reflective mode.Additionally, the spatial efficiency of the pixel region increases dueto the fact that the column spacer 170 is disposed in a positioncorresponding to the through hole TH.

FIG. 5 is a schematic diagram illustrating a transflective liquidcrystal display device having a high resolution according to a secondembodiment of the present invention. In FIG. 5, array elements for thecolor filter substrate are only illustrated, and array elements for thearray substrate are not illustrated because those elements are the sameas in the first embodiment shown in FIG. 2.

In FIG. 5, color filters 255 a, 255 b and 255 c are formed in the colorfilter substrate, and through holes TH are formed in the color filters255 a, 255 b and 255 c. The through holes TH may be can be formed inevery color filters, or only formed in one or two of the color filters255 a, 255 b and 255 c. In the second embodiment shown in FIG. 5, thethrough holes TH are formed in two of the color filters, e.g., in thered (R) and green (G) color filters 255 a and 255 b. In such aconfiguration and structure, a column spacer (reference 270 of FIG. 6)is formed only in the blue (B) pixel region where the through hole TH isnot formed. Namely, the column spacers are not formed in the red (R) andgreen (G) pixel regions such that the spaces do not correspond inposition to the through holes TH as compared with the first embodiment.

FIG. 6 is a cross sectional view taken along a line VI-VI of FIG. 5. Anarray substrate 210 and a color filter substrate 250 face each other,and a liquid crystal layer 280 is interposed between the array substrate210 and the color filter substrate 250. Although FIG. 6 does notexplicitly illustrate all elements of the array substrate 210, thoseelements are the same as in FIGS. 2-4. In FIG. 6, a gate insulatinglayer 217 is formed on a first transparent substrate 211, and data lines221 are formed on the gate insulating layer 217. A passivation layer 230is disposed on the gate insulating layer 217 to cover the data lines221. Pixel electrodes 240 are disposed on the passivation layer 230within the pixel regions P. A reflector 245 is formed on the pixelelectrode 240 within each red (R), green (G) or blue (B) pixel region P.Although not shown in FIG. 6 but shown in FIG. 3, the passivation layer230 may not exist in the transmissive area TA in order to double thecell gap in the reflective area RA rather than that in the transmissiveare TA.

In the color filter substrate 250, red (R), green (G) and blue (B) colorfilters 255 a, 255 b and 255 c are also formed on a rear surface of asecond transparent substrate 251. Each of the red (R), green (G) andblue (B) color filters 155 a, 155 b and 155 c corresponds to a pixelregion P. Two of those three color filters, e.g., the red (R) and green(G) color filters, have through holes TH in a position corresponding tothe reflective area (reference RA of FIG. 5). However, the blue (B)color filter does not have any through hole. An overcoat layer 263 isformed on a rear surface of the red (R), green (G) and blue (B) colorfilters 255 a, 255 b and 255 c and functions to protect and planarizethe surfaces of the color filters 255 a, 255 b and 255 c. A commonelectrode 265 is formed on the whole rear surface of overcoat layer 263.In the blue (B) pixel region where the through hole is not formed, acolumn spacer 270 is formed between the array substrate 210 and thecolor filter substrate 250. The spacer 270 may be disposed in thereflective area RA corresponding to the reflector 245. If one of the red(R) and green (G) color filters 255 a and 255 b does not have thethrough hole TH, a column spacer 270 may be formed additionally in thered (R) or blue (B) pixel region P. Namely, the column spacer 270 may beonly formed in the pixel region where the color filter does not have thethrough hole TH.

FIGS. 7A to 7E are cross sectional views illustrating the process stepsof forming the color filter substrate of FIG. 4 according to the presentinvention.

In FIG. 7A, a red (R) color resin 154 is formed on a transparentsubstrate 151 by a coating method. Thereafter, a mask 190 havinglight-transmitting portions T1 and light-shielding portions B1 isdisposed over the red (R) color resin 154, and then a light exposureprocess is performed through the mask 190. If the red (R) color resin154 is a negative type, portions of the red (R) color resin 154, whichcorrespond to the light-transmitting portions T1 of the mask 190 andreceive the light, remain during the developing process. The otherportions of the red (R) color resin 154, which correspond to thelight-shielding portions B1 of the mask 190, are removed during thedeveloping process. Furthermore, a through hole area THA of the red (R)color resin 154, where the through hole (reference TH of FIGS. 2-4) isformed, is not exposed during the exposure process, and then it isremoved during the developing process.

After the above-mentioned exposure and developing process using the mask190, the red (R) color filter 155 a remains with the through hole THtherein, as shown in FIG. 7B.

In the same manner described with reference to FIGS. 7A and 7B, thegreen (G) and blue (B) color filters 155 b and 155 c both having thethrough holes TH are finally formed on the transparent substrate 151, asshown in FIG. 7C. Although FIG. 7C shows that the through holes TH areformed in all color filters 155 a, 155 b and 155 c, only one or twocolor filters may have the through hole TH in consideration of the colorimaging characteristics. Furthermore, the through holes TH are formed inareas corresponding to the reflective area where the reflectors areformed in the array substrate. In the present invention, each throughhole TH has a smaller size than the reflective area.

In FIG. 7D, the overcoat layer 163 is formed over the transparentsubstrate 151 to cover the red (R), green (G) and blue (B) color filters155 a, 155 b and 155 c. The overcoat layer 163 protects and planarizesthe surfaces of those color filters 155 a, 155 b and 155 c.

After forming the overcoat layer 163, a transparent organic material,e.g., benzocyclobutene (BCB), photo-acrylic resin, cytop,perfluorocyclobutene (PFCB), etc., is formed on the whole of theovercoat layer 163. Next, the transparent organic material is patternedso as to form the column spacers 170 in areas corresponding to thethrough hole TH of the color filer. Therefore, each color pixel has onecolumn spacer 170. As previously discussed, the column spacers 170 makeand maintain the cell gap between the color filter substrate and thearray substrate when those substrates are attached to each other.

Although FIG. 7D shows that the column spacers 170 are formed at everythrough hole TH in every color pixel region, it is possible that thecolumn spacer 170 may only be formed in one of the red (R), green (G)and blue (B) color pixel regions. Furthermore, if one or two of thecolor filters 155 a, 155 b and 155 c does not have any through hole TH,the column spacers 170 may only be formed in the pixel region where thethrough hole does not exist.

Next in FIG. 7E, a transparent conductive material, for example,Indium-Tin-Oxide (ITO) or Indium-Zinc-Oxide (IZO), is deposited on theentire exposed portions of the overcoat layer 163, thereby forming thecommon electrode 165. Therefore, the color filter substrate is finallycomplete.

According to the present invention, because the through holes are formedin the color filters, especially in positions corresponding to thereflective area, the transflective liquid crystal display device mayhave improved brightness and well-balanced color purity regardless ofwhether it is operated in the reflective or transmissive mode.Furthermore, because the black matrix is not formed in the color filtersubstrate, the manufacturing yield increases dramatically and the costof production decreases. In the present invention, because the columnspacer is formed in the reflective area corresponding to the throughhole or in the pixel region where the through hole is not formed, therewill be no limitation in designing and utilizing a reflective area inthe transflective liquid crystal display device having high resolution.The transflective liquid crystal display device of the present inventionmay produce the images with high resolution and high brightness.

It will be apparent to those skilled in the art that variousmodifications and variations may be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A transflective liquid crystal display device, comprising: first andsecond transparent substrates facing each other with a reflectiveportion and a transmissive portion; gate and data lines over the firsttransparent substrate perpendicularly crossing each other and definingpixel regions; a thin film transistor connected the gate and data linesnear in the pixel region; an insulator in the thin film transistor onthe first substrate with covering the gate line; a passivation layer inthe reflective portion on the insulator and on the thin film transistor;a pixel electrode in the reflective and transmissive portions, whereinthe pixel electrode contacts both the passivation layer in thereflective portion and the insulator in the transmissive portion; areflector on the pixel electrode within the reflective portion; red,green and blue color filters on a rear surface of the second transparentsubstrate, the red, green and blue color filters corresponding to pixelregions, wherein some of the red, green and blue color filters havethrough holes and some do not have through holes; column spacers betweenthe reflector and the color filters, each column spacer corresponding inposition to a color filter that does not have a through hole; a commonelectrode under the color filters; and a liquid crystal layer interposedbetween the common electrode and the pixel electrode.
 2. The deviceaccording to claim 1, wherein the through holes and the column spacersare in the reflective portion.
 3. The device according to claim 1,further comprising an overcoat layer between the color filters andcommon electrode.
 4. The device according to claim 1, wherein the columnspacers are formed on the common electrode.
 5. The device according toclaim 1, wherein the passivation layer has a contact hole exposing aportion of the thin film transistor and the pixel electrode contacts thethin film transistor through the contact hole.
 6. The device accordingto claim 1, wherein the column spacers includes one of benzocyclobutene(BCB), photo-acrylic resin, cytop and perfluorocyclobutene (PFCB). 7.The device according to claim 1, wherein the pixel electrode overlapsedge portions of the gate and data lines.
 8. The device according toclaim 1, wherein the passivation layer creates a first cell gap in thetransmissive portion and a second cell gap in the reflective portion,and the first cell gap is larger than the second cell gap.